The apparatus of this invention is designed to finish the raw edges of a cut glass workpiece prior to tempering or toughening the workpiece. Also, the finishing of such raw edges eliminates sharp edges, glass chips, and spall which have a tendency to injure operating personnel and others handling the cut glass workpieces.
Common finishing operations generally employ a double-sided operation wherein a pair of opposed grinding wheels or belts are positioned such that a glass workpiece traveling between the grinders or belts is finished on opposing edges. For instance, in U.S. Pat. No. 3,800,477, the glass sheet passes through a pair of endless flexible abrasive belts which seam opposing edges. Upon completion of the finishing operation, the workpiece is rotated 90° on the conveyer by means of a rotating arm unit which grasps the workpiece and rotates with the workpiece to an orientation 90° removed from the original orientation of the workpiece. The glass workpiece is then seamed on its opposing edges. Such double edge finishing systems with rotating arms are at a disadvantage when a variety of workpieces of differing shapes and sizes are processed. The machine must be retooled to accommodate the variety of sizes, thereby creating costly down time in production.
Other common prior art edge finishing techniques include the use of a double edge grinding machine, wherein the glass plates or workpieces are passed along a horizontal conveyer with parallel banks of grinding wheels on each side of the glass plates. Yet another prior art finishing device is shown in U.S. Pat. No. 6,306,015 which teaches the use of one grinding wheel to simultaneously grind opposed edges of two different rigid planar workpieces. The method involves the use of conveyers to move and position the workpieces proximate the grinding heads and reorient the workpieces through the use of conveyers operating at a 90° orientation with respect to each other, thereby allowing the grinding wheel to machine all four sides of the rectangular workpiece.
It is an object of the invention to provide an edge finishing apparatus designed to finish the edges of a workpiece that allows for varying sizes of workpieces to be processed in-line without need for an apparatus changeover to accommodate each workpiece size and shape.
The advantages afforded by the single-sided finishing system of the present invention are numerous. Quantitatively small orders can be produced with production requirements being downloaded from a business system or order system to the glass cutting machines which can produce the glass of differing sizes to be put directly into the finishing system for processing. Thus, less inventory is needed for pre-manufacture. Since the raw glass can be cut to size as needed, the finished stock that might normally be required as inventory is now not necessary. Because there is less inventory required, there is less racking, thereby freeing up valuable production floor space. The finishing system of the present invention is designed to be placed in line with one or more cutting machines which are designed to cut differing custom sizes. The single-sided finishing system of this invention preferably uses diamond grinding wheels for producing a seamed edge or a ground edge or a pencil edge, thereby providing a more varied mix of product with higher manufacturing yields.